Many medical procedures require treating deep tissues using liquid therapeutic agents. For instance, liquid chemotherapeutic agents are often used to treat interstitial spaces from which tumors have been surgically excised.
The theory behind the chemotherapeutic treatment of these excised interstitial spaces is that even a single malignant cell left in the margins of an excised interstitial space can multiply into a new tumor. Therefore the excised interstitial space is treated with toxic chemotherapeutic agents to destroy any remaining malignant cells. Removing tumors from deep within the body, along with a margin of healthy tissue, leaves a substantial space to be treated. The fluid chemotherapeutic agent is often delivered into the space via a catheter. However, due to the extreme toxicity of chemotherapeutic agents and variability in the size of the margin, chemotherapeutic treatment of an excised interstitial space will lead to the destruction of many healthy, and sometimes critical, cells.
The inability to direct chemotherapy agents to specific parts of an excised interstitial space presents several problems for chemotherapy treatment. Due to the large size of the interstitial space relative to areas requiring treatment, it is difficult to obtain predictive infusion of a drug. Also, filling an excised interstitial space results in the use of an excess quantity of the chemotherapeutic agent, which increases the cost of treatment. Increasing the dose of chemotherapeutic agent also increases the amount of the agent absorbed into a patient's system, making it difficult to achieve a therapeutic concentration of a drug locally at a target site within the excised interstitial space without producing unwanted systemic side effects.
Although many drugs are known for the treatment of various diseases of deep tissues, current techniques for delivering those drugs cannot target specific sites within an excised interstitial space. Often, a greater than needed dose of a drug is used and unintended tissue is exposed to the drug. Lack of targeted delivery impacts both the efficacy and economy of these various treatments.
There, thus, remains a need to provide improved methods for delivering fluids to specific deep tissue targets in a more targeted manner.